The real driver of a hangover is alcohol-induced dehydration, and
the only true-blue cure is to steer clear of the adult beverages.

But there may be a few tips and tricks you can deploy to make
New Year's Day bearable — or at least distract you from your
aching head.

Hangover culprits

The main reason your head pounds after too much alcohol is
dehydration. Your liver works overtime while you're partying to
clear alcohol's toxins from your system; meanwhile, alcohol
prompts your kidneys to produce more urine, making you pee more
fluid than usual.

Once you're dehydrated, your body can't flush out all those
toxins your liver has been busily filtering. In addition, alcohol
can irritate your stomach lining, causing nausea, according to
the Mayo Clinic; it can also disrupt your sleep cycle, leading to
grogginess.

Your aching head may be caused, in part, by alcohol expanding
your blood vessels and otherwise promoting inflammation.
Compounds called cogeners, which are byproducts of fermentation,
can worsen a hangover.

Darker liquors have more cogeners than light ones, meaning that a
night of quaffing bourbon may
leave you in more pain than too many vodka shots.

Still, any alcohol will do. According to a study published in
March 2010 in the journal Alcoholism: Clinical & Experimental
Research, bourbon drinkers felt worse than vodka drinkers the
next day, but both groups slept about the same and neither did
any worse on tricky cognitive tasks.

Myths and cures

Hydration (and a full stomach to slow alcohol absorption) can
protect you from morning-after woes on party night, Aaron
Michelfelder of the Loyola University Health System told
LiveScience
last year.

Following each alcoholic beverage with a glass of water will help
keep your body's toxin-flushing system chugging, Michelfelder
said. Ideally, it will also slow you down; Michelfelder
recommended no more than five drinks for men and three for women
in a three-hour period.

Be aware that the drink you order at the bar is not the same as
the drink that public health researchers talk about. A pint of
beer, for example, is 4 ounces more than a 12-ounce serving of
regular beer. Microbrews and ice beers that are higher in alcohol
may also pack more than a single "drink" even in a 12-ounce
glass. [10
Intoxicating Facts About Beer]

A standard 1.5-ounce shot of liquor is a drink, but most
cocktails boast at least a couple of shots. That one margarita
may be a couple of drinks, or even three.

A recent study suggests that downing a mess of asparagus leaves
(the part no one eats) may counteract the toxic effect alcohol
has on the liver. However, the study, published in 2009, treated
human and rat liver cells with
asparagus extracts rather than having actual drinkers go on
an asparagus binge, so the real-world applicability of this
preventative measure remains unknown.

If moderation isn't in the cards, you're probably going to have
some discomfort. Only about 23 percent of people are genetically
resistant to hangovers, according to a 2008 study published in
the journal Current Drug Abuse Reviews. The rest will have to
make do with sketchy pills, none
of which have been shown to work, and rest and rehydration.

"After you drink too much and wake up with a hangover, the most
important thing is rehydration," Michelfelder said. "Drink water
or drink Gatorade; either is fine."